Period blood clots
By Dr (TCM) Attilio D'Alberto | Traditional Chinese Medicine Practitioner, Wokingham
On this page
- Overview
- What is normal?
- When are blood clots a problem?
- Common causes
- Period blood clots in Chinese medicine
- Acupuncture for menstrual blood clots
- Chinese herbal medicine
- Diet and lifestyle
- When to see a doctor
- Frequently asked questions
1. Overview
Most women will pass small clots during a period at some point in their reproductive lives. Small, occasional clots — up to about the size of a 5p coin — are usually a normal feature of menstruation. Larger, frequent or jelly-like clots, particularly when accompanied by heavy bleeding, severe pain or fatigue, often point to an underlying issue worth investigating.
This page explains what menstrual clots are, when they should and should not cause concern, the most common medical causes, and how Chinese medicine views and treats them.
2. What is normal?
A period clot is a clump of menstrual blood mixed with pieces of uterine lining. Clots form when blood pools in the uterus or vagina faster than the body’s natural anticoagulants (mostly heparin and plasmin) can keep it liquid. As the body slows the flow, fibrin protein binds the cells together and a clot is formed.
Small clots passed during the heaviest one or two days of the period — particularly first thing in the morning after lying down overnight — are normal. They tend to be:
- Smaller than a 10p coin (less than about 2.5 cm across)
- Dark red or brownish in colour
- Occasional rather than continuous
- Not associated with severe pain or feelings of light-headedness
3. When are blood clots a problem?
Period clots are more likely to indicate a problem when they are:
- Large — bigger than a 10p coin (about 2.5 cm) or the size of a 50p coin or larger
- Frequent — passed throughout most of the period rather than just on the heaviest day
- Jelly-like — thick, gelatinous and stringy
- Bright red rather than dark
- Accompanied by heavy bleeding — soaking through a pad or tampon every hour for several hours, needing double protection, or flooding
- Painful — with severe cramping or sharp pain
- Causing other symptoms such as dizziness, fatigue, breathlessness, or pale appearance (which may indicate anaemia)
If you are passing large clots or bleeding heavily, see your GP. Persistent heavy menstrual bleeding (menorrhagia) is one of the most common reasons women are referred for gynaecological assessment in the UK and is almost always treatable. See period won’t stop.
4. Common causes
Fibroids
Uterine fibroids are non-cancerous growths in the wall of the uterus, ranging from a few millimetres to 20+ centimetres in diameter. Submucosal fibroids (those bulging into the uterine cavity) are the most likely to cause heavy bleeding and large clots, because they distort the cavity and increase the surface area of the lining that sheds.
Adenomyosis
Adenomyosis is a condition in which the cells of the uterine lining grow into the muscular wall of the uterus. It causes the uterus to enlarge and bleed more heavily during periods, often with significant pain and large dark clots.
Endometriosis
Endometriosis can cause heavy, painful periods with clots, particularly when there is associated adenomyosis or when the lesions affect the function of the uterus and ovaries.
Hormonal imbalance
An imbalance between oestrogen and progesterone — particularly oestrogen excess, sometimes called oestrogen dominance — can cause the uterine lining to become unusually thick during the cycle, leading to heavier bleeding and larger clots when it sheds. This is most common around perimenopause but can occur at any age. See how to flush excess oestrogen.
Polyps
Endometrial polyps are small benign growths of the uterine lining. They can cause unpredictable heavy bleeding with clots and bleeding between periods.
Miscarriage
Heavy bleeding with large clots in early pregnancy may indicate miscarriage. If you are pregnant or could be pregnant and are bleeding heavily, contact your maternity unit or attend A&E.
Bleeding disorders and medication
Inherited bleeding disorders such as von Willebrand disease, low platelets, and anticoagulant medications all increase menstrual bleeding and clotting. Iron-deficiency anaemia itself can also worsen heavy bleeding by impairing the contraction of the uterine muscle.
5. Period blood clots in Chinese medicine
In traditional Chinese medicine (TCM), menstrual clots are almost always understood as a sign of blood stasis — a pattern in which blood is not flowing freely through the vessels and uterus. Blood stasis can arise from a number of underlying patterns:
Cold in the uterus with blood stasis
Periods are dark, with small to moderate dark clots, accompanied by sharp lower abdominal pain that is relieved by warmth (a hot water bottle, for example). The woman often feels cold, particularly in the lower abdomen and feet.
Liver qi stagnation with blood stasis
Periods are clotted, often with pre-menstrual breast tenderness, irritability and mood swings. Pain is more cramping and distending than sharp. Stress typically makes the symptoms worse.
Heat in the blood with blood stasis
Periods are heavy, bright red, with clots that may be jelly-like, often early in the cycle. There may be a feeling of heat, thirst, irritability and a red tongue.
Blood deficiency with blood stasis
Periods are scanty initially with brown spotting, then progress to a heavier flow with dark clots. The woman is often pale, fatigued, with dry hair and skin and a tendency to dizziness.
Qi deficiency
Periods are heavy, pale and watery with small clots, accompanied by tiredness, breathlessness on exertion and a feeling of heaviness. The woman’s qi is too weak to hold the blood in the vessels.
6. Acupuncture for menstrual blood clots
Acupuncture works on menstrual clots by improving blood flow through the uterus and pelvic vessels, regulating the hormonal control of the cycle, reducing local inflammation, and warming the lower abdomen if Cold is the underlying pattern. In clinical practice I find that 6–12 weekly sessions are typically needed to make a meaningful difference, with treatment ideally focused on the second half of the cycle and the first day or two of the period itself.
Acupuncture is particularly effective when the clots are associated with painful periods or with stress-related cycles. Where the underlying cause is structural — large fibroids, polyps or significant adenomyosis — acupuncture is best used as adjunctive treatment alongside medical management.
7. Chinese herbal medicine
Chinese herbal medicine is one of the most powerful treatments for blood stasis patterns of the menstrual cycle. Formulae are tailored to the underlying pattern, typically combining herbs that move blood (such as Dang Gui, Chuan Xiong and Tao Ren), warm the channels (Ai Ye, Rou Gui), regulate Liver qi (Chai Hu, Xiang Fu) and where appropriate clear heat or tonify deficiency.
I prescribe pharmaceutical-grade granules from Sun Ten in Taiwan. Treatment is usually over 3–6 menstrual cycles to achieve a stable improvement.
8. Diet and lifestyle
- Stay warm in the days before and during your period, especially the lower abdomen and feet. Avoid cold drinks, ice cream and raw cold foods at this time.
- Iron — replace iron lost through heavy bleeding by including red meat, dark leafy greens, lentils, pumpkin seeds and dried apricots in your diet. See what to eat during your period.
- Reduce inflammation — minimise highly processed foods, trans fats, refined sugar and excessive alcohol.
- Move regularly — gentle daily exercise improves pelvic circulation and reduces blood stasis. Avoid intense exercise during the period.
- Manage stress — chronic stress drives Liver qi stagnation, the leading TCM cause of clotted periods.
- Heat application — a hot water bottle on the lower abdomen during the period eases cramps and may reduce clotting.
9. When to see a doctor
See your GP urgently if you experience any of the following:
- Soaking through a pad or tampon every hour for several hours in a row
- Passing clots larger than the size of a 50p coin
- Bleeding lasting longer than 7 days
- Bleeding between periods or after sex
- Symptoms of anaemia — persistent fatigue, breathlessness, dizziness, pale appearance
- Heavy bleeding and you are or could be pregnant
- Heavy bleeding with severe pain that is not relieved by usual painkillers
10. Frequently asked questions
Are blood clots in your period normal?
Small occasional clots up to about the size of a 10p coin are normal during the heaviest day or two of a period. Larger, frequent or jelly-like clots, especially with heavy bleeding or severe pain, are not normal and should be investigated.
Why am I passing large blood clots during my period?
The most common causes of large period clots are uterine fibroids, adenomyosis, hormonal imbalance (particularly oestrogen excess), polyps and endometriosis. From a Chinese medicine perspective, large clots almost always reflect blood stasis — impaired flow of blood through the uterus.
Is jelly-like blood clots during period normal?
Occasional small jelly-like clots can be normal — they are simply the body’s anticoagulants being temporarily overwhelmed by a heavy flow. Frequent, large or persistent jelly-like clots, particularly with heavy bleeding, suggest an underlying cause that should be assessed by your GP.
Can stress cause period blood clots?
Yes — chronic stress is one of the leading causes of clotted, painful periods in modern practice. In Chinese medicine this is the pattern of Liver qi stagnation leading to blood stasis.
Can acupuncture help with period clots?
Yes. Acupuncture improves blood flow through the uterus and pelvic vessels, regulates the hormonal control of the cycle and warms the lower abdomen where appropriate. Most patients see meaningful improvement within 3–4 menstrual cycles of consistent weekly treatment.
What foods help reduce period blood clots?
Anti-inflammatory foods (oily fish, leafy greens, nuts, seeds, berries), iron-rich foods (red meat, lentils, dark green vegetables) and warming foods (ginger, cinnamon, soups, slow-cooked stews) are all helpful. Reduce highly processed foods, refined sugar, cold drinks and excessive alcohol.
To discuss your specific menstrual symptoms, contact me or book a consultation at my Wokingham, Berkshire clinic.
